1242121289 has 2 divisors, whose sum is σ = 1242121290. Its totient is φ = 1242121288.

The previous prime is 1242121271. The next prime is 1242121327. The reversal of 1242121289 is 9821212421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1163355664 + 78765625 = 34108^2 + 8875^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1242121289 is a prime.

It is not a weakly prime, because it can be changed into another prime (1242121229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621060644 + 621060645.

It is an arithmetic number, because the mean of its divisors is an integer number (621060645).

Almost surely, 2^1242121289 is an apocalyptic number.

It is an amenable number.

1242121289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242121289 is an equidigital number, since it uses as much as digits as its factorization.

1242121289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 32.

The square root of 1242121289 is about 35243.7411322918. The cubic root of 1242121289 is about 1074.9493508497.

The spelling of 1242121289 in words is "one billion, two hundred forty-two million, one hundred twenty-one thousand, two hundred eighty-nine".